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2x 5970's and Crossfire

08-16-2010, 06:10 PM

I'm running into some trouble. At this moment I am running on 1 of 4 VPU's which is very frustrating. I've done some searching and tried setting up a chain and enabling it, but all I get is an error saying the platform is not supported. When I reboot, and check the Crossfire status, it is disabled.

There is a message saying it could be enabled via P2P and GART so I did some more googling and found nothing about it.

I'm running into some trouble. At this moment I am running on 1 of 4 VPU's which is very frustrating. I've done some searching and tried setting up a chain and enabling it, but all I get is an error saying the platform is not supported. When I reboot, and check the Crossfire status, it is disabled.

There is a message saying it could be enabled via P2P and GART so I did some more googling and found nothing about it.

Comment

Last I heard Crossfire required - as far as I understood - per-application profiles which really only exist on Windows. I'm not really sure whether it makes much sense to use that kind of a setup for gaming outside Windows. For GPGPU it would probably be quite awesome though. (and even there as two separate cards, not a Crossfire setup)

Comment

Last I heard Crossfire required - as far as I understood - per-application profiles which really only exist on Windows. I'm not really sure whether it makes much sense to use that kind of a setup for gaming outside Windows. For GPGPU it would probably be quite awesome though. (and even there as two separate cards, not a Crossfire setup)

this stuff exists for linux ;-) but yes i do not have a crossfiresystem

Phantom circuit Sequence Reducer Dyslexia

Comment

Last I heard Crossfire required - as far as I understood - per-application profiles which really only exist on Windows. I'm not really sure whether it makes much sense to use that kind of a setup for gaming outside Windows. For GPGPU it would probably be quite awesome though. (and even there as two separate cards, not a Crossfire setup)

I think it should be possible to do multi-GPU rendering in a generic way (although probably not optimally).

A simple way would be to have both cards have the same data in memory.
For each rendering operation, divide the target in two regions (ideally in a tiled pattern), and have each GPU render one region and send results to the other (so they end up with the same final surface).

Vertex shading should be parallelizable too by using stream out with a similar strategy. You could possibly even use a geometry shader to directly send triangles to the right partition in this case.

No open source driver does that though as far as I know, but fglrx seems to have at least some support for Crossfire.

Comment

I think it should be possible to do multi-GPU rendering in a generic way (although probably not optimally).

Could in theory be done and can be done with current driver implementations aren't the same though. Yes, fglrx does "support" Crossfire as in I've read of it being able to recognize Crossfire setups but never heard of anyone actually managing to use it in some program.
But as said earlier, GPGPU using eg Stream SDK or so probably benefits of having two cards regardless of Crossfire.